Six fire engines and around 40 firefighters were called to a fire at a flat in St Dunstans Close in Hayes.
Part of a four room flat on the ground floor of a four-storey block was damaged by the fire. Firefighters rescued one woman from a first floor balcony via a ladder. She was treated on scene by London Ambulance Service crews but not taken to hospital.
Crews led another woman to safety from the second floor via an internal staircase. A third woman left a flat on the third floor and was treated at the scene for smoke inhalation and taken to hospital by London Ambulance Service crews as a precaution.
The Brigade was called at 0136 and the fire was under control by 0213. Fire crews from Hayes, Heathrow, Southall and Hillingdon fire stations attended.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police Service.